Environmental activist group Sea Shepherd is preparing for a three month voyage to the Southern Ocean and is expecting one of its most intense campaigns yet against Japanese whalers.

Three Sea Shepherd vessels – the Steve Irwin, the Bob Barker and the Brigitte Bardot – with a total of 88 crew members will head into Antarctic waters in December for what they call 'Operation Divine Wind' (or Kamikaze) with the objective of stopping Japanese whaling activities.

It's Sea Shepherd's eighth voyage to the Southern Ocean. The organisation claims that its harassment tactics last season forced the Japanese whaling fleet to cut short its hunting trip with a fraction of its usual catch.

"We have no idea what they're going to do, but we do know that the Japanese coast guard and the military will not be involved," Sea Shepherd captain Paul Watson told SBS. "They say it's out of their jurisdiction. So anything the whalers have will have to be private security or mercenaries or they'll have to charter a faster boat."

Sea Shepherd and the whaling fleet have a history of confrontation in the Southern Ocean. The activists' attempts to blockade the 'factory ship' to prevent the whalers from loading and processing their haul have resulted in collisions and damage on both sides. Other harassment tactics include propeller fouling and "illegal boarding" and throwing projectiles.

The whalers, represented by the Institute of Cetacean Research, maintain these harassment tactics are illegal and tantamount to piracy. How they respond this season remains to be seen.

'LOOPHOLE'

Japanese whaling activity in the Southern Ocean is a contentious issue. The area was designated a whale sanctuary by the International Whaling Commission (IWC) in 1994. Japan continues to hunt whales in the sanctuary under an IWC provision permitting whaling for "scientific research". Japan allocates itself a quota of about 1,000 whales, mostly minkes, per year for "research" purposes, but many scientists say this research program fails to meet the standard for credible scientific research.

LEGAL ACTION

Australia "strongly opposes Japanese whaling in the Southern Ocean," says Donna Petrachenko, Australia's commissioner to the International Whaling Commission (IWC).

In May 2010 Australia initiated legal action against Japan in the International Court of Justice. The court has ordered Japan to file its response by March 9th, 2012. Japan is likely to hold fast – as well as its scientific claim it has always disputed the legality of the sanctuary.

"We believe that we have a very strong case, that Japanese whaling is against international law in terms of the international convention on the regulation of whaling," Ms Petrachenko told SBS.

Sea Shepherd's Paul Watson doesn't have much time for diplomatic or legal channels to end whaling and says the Australian government should take stronger action.

"Diplomacy has failed. This court case will go on and on and on and maybe it might get a resolution in 2016 or something in the meantime whales are dying," he told SBS.

"Australia and New Zealand should be down defending these whales in this sanctuary and by ordering the Japanese whaling fleet out of the area. All Australia has to do is show up with a war ship and say 'out of here' there's not going to be any argument, Japan will leave.”

The Bob Barker will leave Hobart in December to head down to the Southern Ocean to be joined by its two sister ships.

VIDEO: The crew of Sea Shepherd vessel Bob Barker show us around their ship and explain what it's like on a trip to the Southern Ocean to chase the whaling fleet.